The present invention is directed to a device for gripping and placing members, such as packages or individual articles, used in automatic handling apparatus, and include gripping arms which are pivotally mounted at one end and grip the member at the other. The pivoted ends can be moved toward and away from one another for effecting gripping engagement with or release of a member.
Known devices of this type, see the brochure of the firm Nutro Maschinenbau GmbH, Nuremburg, "Fuji-Notro Handling-Roboter ACE" where form-locking gripping of a member is effected with the member being gripped on its lower surface, avoid the disadvantages of devices which hold a member in a locking manner by engagement with the upper surface only, for example, by means of pneumatic suction grippers. Where the member is gripped only on its upper side there are the disadvantages that the member can be considerably deformed when lifted and due to such deformation result in stacks of such members being of an inferior quality. Moreover, devices which only grip from above in a force-locking manner make special demands on the quality of the packaging material, for example, cement bags. Such packaging material should be of adequate strength, the material must not be porous and it must have a sufficiently smooth surface whereby the pneumatic suction equipment can be applied. Further, grippers which work in a form-locking manner are also known which have gripping arms for receiving a member between them and such arms are movable in opposite directions relative to one another, note the brochure of the firm Beumer Maschinenfabrik KG, Beckum, "Robotpac- Der Universal-Palettiererautomat".
In both of the devices mentioned above which work in a form-locking manner, there is the disadvantage that they do not permit placement of the member on a surface where it is laterally enclosed on all sides, that is, placement of the member in a space laterally enclosed by similarly placed members.